alert tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (msg:"BLEEDING-EDGE CURRENT_EVENTS Unknown Proxy Method/Bot Successful Connect Packet Packet"; flowbits:isset,BS.BPset; flow:established,to_server; dsize:16; content:"|9a 02 08 00|"; offset:0; depth:4; flowbits:set,BS.BPcheckin; tag:session; classtype:trojan-activity; reference:url,doc.bleedingthreats.net/2006396; sid:2006397; rev:1;)
Added 2007-07-16 05:16:13 UTC
Bot is using port 80 in an interesting way. Agent makes an outbound port 80 connection, sends a checkin, gets a command back of what IP and port to connect to. Then sends a connection successful type of packet, then streams whatever the controller sends trough the agent.
Initial packet from the agent looks like so:
24 bytes
09 02 06 00 25 ab 3f .....
Agent replies with:
10 bytes
9a 02 07 00 xx xx xx xx 00 yy
the x's are the IP to connect to, y being the port
Agent then makes the connection and replies wth something like:
16 bytes
9a 02 08 00 00 00 ...
The agent then started proxying the connection direct between controller.
More info as I get it
Matt
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MattJonkman - 16 Jul 2007